This is WEEKEND EDITION from NPR News. I'm Linda Wertheimer in for Scott Simon.

Next week, the 113th Congress will convene and they may or may not be wrangling with the fiscal cliff issue. What we do know about this incoming Congress is that it will the most diverse in the nation's history. As the year comes to a close, we're meeting some of those new members. Today, NPR's Karen Grigsby Bates introduces us to Democrat Raul Ruiz, a physician who gave up his practice to run for office representing the Palm Springs area in Southern California.

KAREN GRIGSBY BATES, BYLINE: If you want an interview with the new representative of California's 36th district, you will have to possess a lot of persistence. Earnest and unfailingly polite, baby-faced 40-year-old Raul Ruiz always makes time to speak with anyone who approaches him.

BATES: And promises to follow up on several requests when he gets to Washington. Then, just as he's within grasp, an elder from a local Native American community takes him by the arm.

UNIDENTIFIED MAN #2: I need to talk with you for a minute. Were you walking down this way?

RUIZ: OK.

BATES: And it starts all over again.

So has this been your regular day at lunch for the last couple of...

RUIZ: Weeks? Yes.

BATES: Are you ever going to get any time to yourself?

RUIZ: Yes, when I spend time in the evenings and after a long day, I go home. It's a good time to have some solitude.

BATES: There hasn't been a whole lot of opportunity for that in the past year, since Ruiz decided to leave his chosen career - emergency medicine - to run for Republican Mary Bono Mack's seat. It was a nasty campaign. Bono Mack's ads painted Ruiz as radical and un-American.

(SOUNDBITE OF POLITICAL AD)

BATES: Redistricting changed the demographics in the 36th District; it's in the low desert near Palm Springs, and it put more Latino voters within its borders. That helped, but Ruiz's personality - upbeat and inclusive - earned him voter approval across ethnic lines. And it didn't hurt that he had a life story that resonated with an electorate that was growing more diverse each year.

At the only debate with Bono Mack, Ruiz told the audience when he wanted to go to college, he'd asked small businessmen in his community to invest in his education. And he told them what they'd get in return.

RUIZ: I promised to come back as a doctor, and with their help, I went to UCLA and then to Harvard Medical School where I became the first Latino to receive three graduate degrees from Harvard.

BATES: Raul Ruiz is not only a graduate of Harvard's medical school, he holds a master's degree in public policy from its Kennedy School and another master's from its school of public health. And although that trifecta would have earned him a ticket to anywhere in the U.S., Dr. Ruiz kept to his original plan.

RUIZ: True to my promise, I came home as an E.R. doctor at Eisenhower Medical Center.

BATES: It's the area's only nonprofit hospital; many of its patients are uninsured. Ruiz's interest in medicine goes well beyond the emergency room to public policy issues that affect public health.

Which brings us to this freezing afternoon at the edge of the Salton Sea, a legendarily polluted body of water with major air quality issues. Ruiz tells his listeners the shrinking sea's exposed shores are a factor in the area's pediatric asthma rates; asthma sends a disproportionate number of children to his E.R. weekly.

RUIZ: It breaks our heart when we see a young child struggling to breathe, and if the sea dissipates, we will have a dust bed that will aggravate those problems.

BATES: Raul Ruiz says it pains him to leave his patients and community. But although he's off to Congress, he's not giving up medicine completely. He's already making plans to volunteer in physician-short parts of D.C. in his spare time. How much of that he'll have, though, is anybody's guess.